drivers/platform/x86: Add driver for INT0002 ACPI device

Message ID	20170421074157.19159-1-hdegoede@redhat.com (mailing list archive)
State	Not Applicable, archived
Headers	show Return-Path: <linux-acpi-owner@kernel.org> DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 37CB0C054C5A From: Hans de Goede <hdegoede@redhat.com> To: Darren Hart <dvhart@infradead.org>, Andy Shevchenko <andy@infradead.org> Cc: Hans de Goede <hdegoede@redhat.com>, linux-acpi@vger.kernel.org, platform-driver-x86@vger.kernel.org, Takashi Iwai <tiwai@suse.de> Subject: [PATCH] drivers/platform/x86: Add driver for INT0002 ACPI device Date: Fri, 21 Apr 2017 09:41:57 +0200 Message-Id: <20170421074157.19159-1-hdegoede@redhat.com> Sender: linux-acpi-owner@vger.kernel.org Precedence: bulk

diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig index 53afa78..c400e29 100644 --- a/drivers/platform/x86/Kconfig +++ b/drivers/platform/x86/Kconfig @@ -889,6 +889,16 @@ config INTEL_PMC_CORE Supported features: - SLP_S0_RESIDENCY counter. +config INTEL_INT0002 + tristate "Intel INT0002 Virtual GPIO ACPI device driver" + depends on X86 && ACPI + ---help--- + Some peripherals on Baytrail and Cherrytrail platforms signal + PME to the PMC to wakeup the system. When this happens software + needs to explictly clear the interrupt source to avoid an IRQ + storm on IRQ 9. This is modelled in ACPI through the INT0002 + ACPI device. This driver implements the clearing of the IRQ. + config IBM_RTL tristate "Device driver to enable PRTL support" depends on PCI diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile index 6731893..de4ffb5 100644 --- a/drivers/platform/x86/Makefile +++ b/drivers/platform/x86/Makefile @@ -51,6 +51,7 @@ obj-$(CONFIG_INTEL_SCU_IPC) += intel_scu_ipc.o obj-$(CONFIG_INTEL_SCU_IPC_UTIL) += intel_scu_ipcutil.o obj-$(CONFIG_INTEL_MFLD_THERMAL) += intel_mid_thermal.o obj-$(CONFIG_INTEL_IPS) += intel_ips.o +obj-$(CONFIG_INTEL_INT0002) += intel_int0002.o obj-$(CONFIG_XO1_RFKILL) += xo1-rfkill.o obj-$(CONFIG_XO15_EBOOK) += xo15-ebook.o obj-$(CONFIG_IBM_RTL) += ibm_rtl.o diff --git a/drivers/platform/x86/intel_int0002.c b/drivers/platform/x86/intel_int0002.c new file mode 100644 index 0000000..76220db --- /dev/null +++ b/drivers/platform/x86/intel_int0002.c @@ -0,0 +1,232 @@ +/* + * Intel INT0002 "Virtual GPIO" driver + * + * Copyright (C) 2017 Hans de Goede <hdegoede@redhat.com> + * + * Loosely based on android x86 kernel code which is: + * + * Copyright (c) 2014, Intel Corporation. + * + * Author: Dyut Kumar Sil <dyut.k.sil@intel.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * Some peripherals on Baytrail and Cherrytrail platforms signal PME to the + * PMC to wakeup the system. When this happens software needs to clear the + * PME_B0_STS bit in the GPE0a_STS register to avoid an IRQ storm on IRQ 9. + * + * This is modelled in ACPI through the INT0002 ACPI device, which is + * called a "Virtual GPIO controller" in ACPI because it defines the event + * handler to call when the PME triggers through _AEI and _L02 / _E02 + * methods as would be done for a real GPIO interrupt. + * + * This driver will bind to the INT0002 device, call the ACPI event handler + * for the wakeup and clear the interrupt source avoiding the irq storm. + */ + +#include <asm/cpu_device_id.h> +#include <asm/intel-family.h> +#include <asm/io.h> +#include <linux/acpi.h> +#include <linux/interrupt.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/pm_runtime.h> +#include <linux/slab.h> + +#define GPE0A_PME_STS_BIT 0x2000 +#define GPE0A_PME_EN_BIT 0x2000 +#define GPE0A_STS_PORT 0x420 +#define GPE0A_EN_PORT 0x428 + +#define ICPU(model) { X86_VENDOR_INTEL, 6, model, X86_FEATURE_ANY, } + +static const struct x86_cpu_id int0002_cpu_ids[] = { +/* + * Limit ourselves to Cherry Trail for now, until testing shows we + * need to handle the INT0002 device on Baytrail too. + * ICPU(INTEL_FAM6_ATOM_SILVERMONT1), * Valleyview, Bay Trail * + */ + ICPU(INTEL_FAM6_ATOM_AIRMONT), /* Braswell, Cherry Trail */ + {} +}; + +struct int0002_data { + struct spinlock lock; + struct device *dev; + const struct x86_cpu_id *cpu_id; + acpi_handle handle; + char ev_name[5]; +}; + +static void int0002_irq_enable(struct int0002_data *data, bool enable) +{ + unsigned long flags; + u32 gpe_en_reg; + + spin_lock_irqsave(&data->lock, flags); + + gpe_en_reg = inl(GPE0A_EN_PORT); + if (enable) + gpe_en_reg |= GPE0A_PME_EN_BIT; + else + gpe_en_reg &= ~GPE0A_PME_EN_BIT; + outl(gpe_en_reg, GPE0A_EN_PORT); + + spin_unlock_irqrestore(&data->lock, flags); +} + +static irqreturn_t int0002_irq_handler(int irq, void *handler_data) +{ + struct int0002_data *data = handler_data; + u32 gpe_sts_reg; + + gpe_sts_reg = inl(GPE0A_STS_PORT); + if (!(gpe_sts_reg & GPE0A_PME_STS_BIT)) + return IRQ_NONE; + + int0002_irq_enable(data, false); + + return IRQ_WAKE_THREAD; +} + +static irqreturn_t int0002_irq_thread(int irq, void *handler_data) +{ + struct int0002_data *data = handler_data; + acpi_status status; + + /* Don't call ACPI event handler on Baytrail? Taken from Android-x86 */ + if (data->cpu_id->model != INTEL_FAM6_ATOM_SILVERMONT1) { + status = acpi_evaluate_object(data->handle, data->ev_name, + NULL, NULL); + if (ACPI_FAILURE(status)) + dev_err(data->dev, "Error calling %s\n", data->ev_name); + } + + /* Ack and then re-enable IRQ */ + outl(GPE0A_PME_STS_BIT, GPE0A_STS_PORT); + int0002_irq_enable(data, true); + + return IRQ_HANDLED; +} + +static int int0002_probe(struct platform_device *pdev) +{ + struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER, NULL }; + struct device *dev = &pdev->dev; + struct int0002_data *data; + struct acpi_resource *res; + acpi_status status; + acpi_handle hdl; + int irq, ret; + + data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); + if (!data) { + dev_err(dev, "can't allocate memory for int0002\n"); + return -ENOMEM; + } + + spin_lock_init(&data->lock); + data->dev = dev; + + /* Menlow has a different INT0002 device? <sigh> */ + data->cpu_id = x86_match_cpu(int0002_cpu_ids); + if (!data->cpu_id) + return -ENODEV; + + data->handle = ACPI_HANDLE(dev); + if (!data->handle) + return -ENODEV; + + irq = platform_get_irq(pdev, 0); + if (irq < 0) { + dev_err(dev, "Error getting IRQ: %d\n", irq); + return irq; + } + + status = acpi_get_event_resources(data->handle, &buf); + if (ACPI_FAILURE(status)) { + dev_err(dev, "Error getting acpi event resources\n"); + return -ENODEV; + } + + /* Find the "GPIO interrupt" event handler to call upon PME */ + ret = -ENODEV; + for (res = buf.pointer; + res && (res->type != ACPI_RESOURCE_TYPE_END_TAG); + res = ACPI_NEXT_RESOURCE(res)) { + + if (res->type != ACPI_RESOURCE_TYPE_GPIO || + res->data.gpio.connection_type != + ACPI_RESOURCE_GPIO_TYPE_INT) + continue; + + snprintf(data->ev_name, sizeof(data->ev_name), "_%c%02X", + res->data.gpio.triggering ? 'E' : 'L', + res->data.gpio.pin_table[0]); + + status = acpi_get_handle(data->handle, data->ev_name, &hdl); + if (ACPI_SUCCESS(status)) { + ret = 0; + break; + } + } + + ACPI_FREE(buf.pointer); + + if (ret) { + dev_err(dev, "Error could not find event handler\n"); + return ret; + } + + ret = devm_request_threaded_irq(dev, irq, + int0002_irq_handler, int0002_irq_thread, + IRQF_SHARED, "INT0002", data); + if (ret) { + dev_err(dev, "Error requesting IRQ %d: %d\n", irq, ret); + return ret; + } + + int0002_irq_enable(data, true); + + return 0; +} + +static int int0002_runtime_suspend(struct device *dev) +{ + return 0; +} + +static int int0002_runtime_resume(struct device *dev) +{ + return 0; +} + +static const struct dev_pm_ops int0002_pm_ops = { + .runtime_suspend = int0002_runtime_suspend, + .runtime_resume = int0002_runtime_resume, +}; + +static const struct acpi_device_id int0002_acpi_ids[] = { + { "INT0002", 0 }, + { }, +}; +MODULE_DEVICE_TABLE(acpi, int0002_acpi_ids); + +static struct platform_driver int0002_driver = { + .driver = { + .name = "Intel INT0002 Virtual GPIO", + .pm = &int0002_pm_ops, + .acpi_match_table = ACPI_PTR(int0002_acpi_ids), + }, + .probe = int0002_probe, +}; + +module_platform_driver(int0002_driver); + +MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>"); +MODULE_DESCRIPTION("Intel INT0002 Virtual GPIO driver"); +MODULE_LICENSE("GPL");

drivers/platform/x86: Add driver for INT0002 ACPI device

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